Proximate analysis of homogenized and minced mass of pork sausages by NIRS V. Ortiz-Somovilla a, * , F. Espan ˜ a-Espan ˜a a , A.J. Gaita ´n-Jurado a , J. Pe ´rez-Aparicio b , E.J. De Pedro-Sanz c a IFAPA, CIFA ‘‘Alameda del Obispo’’ (A ´ rea de Tecnologı ´a Postcosecha e Industrias Agroalimentarias), Avda. Mene ´ndez Pidal, Apdo. Correos 3.092, 14080 Co ´ rdoba, Spain b IFAPA, CIFA ‘‘Palma del Rı ´o’’(A ´ rea de Tecnologı ´a Postcosecha e Industrias Agroalimentarias), Avda Rodrı ´guez de la Fuente s/n, Apdo. 29, 14700 Palma del Rı ´o, Co ´ rdoba, Spain c Universidad de Co ´ rdoba, Departamento de Produccio ´ n Animal, Campus Rabanales, Edificio Produccio ´ n Animal, 14014 Co ´ rdoba, Spain Received 15 August 2005; received in revised form 23 February 2006; accepted 23 February 2006 Abstract Near infrared spectroscopy was employed to analyse samples of pork sausage meat used in the manufacturing of typical Spanish sau- sages (minced and homogenized product). As well, two modes of analysis for the instrument were compared. Data from proximate anal- ysis (fat, moisture and protein) were put into a calibration model by a diode array NIR spectrometer. The spectral range used was 515– 1650 nm and different mathematical pre-treatments on the signal (derivatives and scatter corrections) were also compared. Different mathematical pre-treatments caused considerable changes in the statistics of the models (coefficients of determination and standard errors). R 2 (calibration) and standard errors of prediction (SEP, external validation) in minced sausage meat for fat, moisture and protein were 0.98, 0.98 and 0.93 (R 2 ) and 1.38%, 1%, 0.83% (SEP), respectively. These values in homogenised sausage meat for fat, moisture and protein were 0.99, 0.98 and 0.93 (R 2 ), and 0.94%, 0.76% and 0.87% (SEP), respectively. Ó 2006 Elsevier Ltd. All rights reserved. Keywords: Pork processed; Proximate analysis; NIRS; Quality control; Sample presentation 1. Introduction The meat trade plays an important role in the food and agricultural industry overall, providing added value to its economy. Specifically, in Spain, the pork trade is of partic- ular importance, making up 30.2% of the final livestock production and 10.4% of the final agrarian production (MAPA, 2004). Thus, Spain is the second largest producing country in the European Union, after Germany, account- ing for 18.6% of the total production in 2003, and 3.8% on a global scale. Dry-cured pork sausages are widely consumed in Spain, and the production of the typical ‘‘salchicho ´n’’ sausage is particularly important. This sausage is obtained in the same way as other dry-cured sausages, after mixing, casing, fermentation and ripening. In order to manufacture this 0308-8146/$ - see front matter Ó 2006 Elsevier Ltd. All rights reserved. doi:10.1016/j.foodchem.2006.02.058 Abbreviations: CIFA, Research and Development Agrarian Center of Andalusia Government; HD, sample presentation Homogenized ‘Down- view’; HU, sample presentation Homogenized ‘Up-view’; IFAPA, Anda- lusia Institute of Research and Development Agrarian, Fishing, Food and Ecologic Production; MD, sample presentation Minced ‘Down-view’; MPLS, modified partial least squared; MSC, multiplicative scatter corre- ction; MU, sample presentation Minced ‘Up-view’; PCA, principal com- ponent analysis; PCR, principal components regression; R 2 , coefficient of determination in calibration; r 2 , coefficient of determination in cross val- idation; RMS, root mean squared; RPD, residual predictive deviation; SEC, standard error of calibration; SECV, standard error of cross valid- ation; SEP, standard error of prediction; SNDDT, Standard normal va- riate and detrend; STD, standard deviation. * Corresponding author. Tel.: +34 957 016001; fax: + 34 957 016043. E-mail address: victor.ortiz@juntadeandalucia.es (V. Ortiz-Somovilla). www.elsevier.com/locate/foodchem Food Chemistry xxx (2006) xxx–xxx Food Chemistry ARTICLE IN PRESS